Vascular endothelial growth factor levels in patients with obstructive sleep apnea: a meta-analysis

Published articles regarding the blood levels of vascular endothelial growth factor (VEGF) in obstructive sleep apnea (OSA) patients are contradictory. The objective of this study was to explore whether VEGF levels is high or not in OSA subjects via quantitatively statistical analysis. The electronic databases of Pubmed, Web of Science, EMBASE were systematic searched. The VEGF levels and clinical characteristics of participants between OSA group and control group were extracted for analysis. Weighted mean difference (WMD) or standard mean difference (SMD) with 95 % confidence interval (CI) was calculated by fixed effects or random effects model. Appropriate statistical software was employed for data synthesis. Totaling 15 articles with 697 participants were included in this study. Pooled meta-analysis showed that blood VEGF concentrations were significantly higher in OSA patients than in control subjects (SMD 1.89, 95 % CI 0.92-2.87, p = 0.000). Subgroup analysis demonstrated that when compared with control group, OSA patients with age ≥50 years (SMD 2.54, 95 % CI 1.28-3.80, p = 0.000), apnea hypopnea index ≥30 events/h (SMD 2.47, 95 % CI 1.20-3.73, p = 0.000) had higher VEGF levels. Compared with control subjects, OSA patients had an elevated VEGF in serum (SMD 3.55, 95 % CI 1.82-5.28, p = 0.000) rather than in plasma. High blood VEGF concentrations were observed in OSA patients, particularly in the older and more serious patients.